Stop system for determining the normal sector of freedom of movement of a door knob



June 11, 1963 M E. WILLIAMS 3,093,400

STOP SYSTEM FOR DETERMINING THE NORMAL SECTOR 0F FREEDOM OF MOVEMENT OF A DOOR KNOB Filed Aug. 8, 1960 I8 24 FIG.

MURRAY E. WILLIAMS INVENTOR.

BY W 15.50%

Unite This invention relates to the construction of door latches, and particularly to a system for determining the normal freedom of rotary movement of a door knob retracting the latch bolt. It is desirable that this sector be determined independently of the operating latch mechanism in order to prevent the transfer of excessive strains to a structure which should not be required to resist abuse. The stop structure should provide a sector of movement adequate to operate the 'bolt of the door latch without permitting such an excess of movement as would distort the components of the mechanism. The present invention provides a very simple and effective means for transferring any excess torque directly from the knob sleeve over to the door structure surrounding the latch mechanism without involving the latch mechanism itself. This broad concept is not totally new, but the structure provided by this invention permits this feature to be utilized very economically and with a minimum of maintenance requirements. The several features of this invention will be analyzed in detail through the discussion of the particular embodiments illustrated in the accompanying drawing. In the drawing:

FIGURE 1 presents a perspective view, partially in section, showing the normal free position of the device prior to the actuation of the door knob.

FIGURE 2 presents a perspective view, also partially in section, and showing the engagement of the stop mechanism for limiting the rotary movement of the knob sleeve.

FIGURE 3 presents a perspective view of the locking plate used in conjunction with the structure illustrated in FIGURES 1 and 2.

Referring to the drawing, the views illustrate a unit, commonly known as a cylindrical mechanism for retracting a latch bolt. The frame generally indicated at 10 supports the retractor 11 for reciprocating sliding movement. The jaws 12 of the retractor engage the stem (not shown) of a latch bolt for retracting the same when it is desired to open the door. Movement of the retractor 11 is induced by rotation of the knob sleeves 13 or 14 by the associated knobs (not shown), this operation taking place in the conventional fashion through the functioning of roll-back cams normally at the inner ends of the sleeves 13 and 14. This portion of the mechanism is conventional, and forms no part of this invention.

The frame 10, in the illustrated form of the invention, is generally similar at the axially opposite sides of the latch (with respect to the axis of the sleeves 13 and 14). Each side includes a knob-supporting member indicated generally at 15. This member includes a cylindrical bearing portion 16 for rotatably supporting the associated sleeve, the clearance cylindrical portion 17 of somewhat larger inside diameter than that of the bearing portion 16, and the flange portion 18 disposed in a plane perpen- States Patent dicular to the axis of the sleeve. The frame also includes a locking plate 19 preferably mounted against each of the flanges 18. The configuration of the flanges 18 and the plate 19 are axially similar, one being substantially an axial projection of the other. The combinations of the plates 19 and the flanges 18 at the opposite sides of the latch mechanism are held in the assembled relationship by the intermediate frame member 20. The effect of the intermediate frame member 20 is to maintain the relative angular and axial positions of the plates 19 and the flanges 18, and these components may therefore be considered as normally fixed with respect to each other. The details of the engagement of the components constituting the frame 10 are shown and described in the application of Murray E. Williams, Serial No. 47,982, filed on August 8, 1960, now abandoned.

The central opening 21 of the plates 19 forms an inner bearing locating the end of the sleeves. The lugs 22 and 23 extend axially within the space defined by the clearance portion 17 of the knob-supporting members 15, and are disposed to clear the outer diameter of the sleeves. Sleeves are therefore free to rotate within the opening 21, until such rotation is interfered with by the engagement of the abutment 24 with either of the lugs 22 or 23. The abutment 24 is preferably a section of the material of the sleeve which is lanced out of cylindrical position so that it extends on an incline with respect to the sleeve into the space existing between the cylindrical outer surface of the sleeve and the inside surface of the clearance portion 17. This abutment therefore moves around a path which is intersected by the lugs 22 or 23, and the result is a limitation of the freedom of movement of the sleeve within the sector .thu-s defined. The normal position determined by the spring mechanism conventionally associated with the retractor 12 is illustrated in FIGURE 1, with the position of the lugs 22 and 23 being disposed to permit the desired degree of rotation of the knob in either direction from the illustrated neutral position. It is noteworthy that the position of the abutment 24, and the fact that it is displaced from the material of the sleeve 13 along axial planes, provide a tremendous amount of strength against the forces encountered through engagement with the lugs 22 and 33. These forces are directly transferred into the plates 19, and from there to the mounting screws (not shown) which engage the holes 25 and 26, these holes being fixed in position with respect to the surrounding door.

The particular embodiments of the present invention which have been illustrated and discussed herein are for illustrative purposes only and are not to be considered as a limitation upon the scope of the appended claim. In this claim, it is our intent to claim the entire invention disclosed herein, except as we are limited by the prior art.

I claim:

In a latch mechanism, a'stop system for establishing the normal sector of freedom of knob rotation, comprising: frame means including a knob-supporting member provided with a cylindrical bearing portion, a clearance cylindrical portion extending from said bearing portion coaxially therewith and of increased diameter over that of said bearing portion, and also having a flange portion containing an opening coaxial with said clearance portion and secured to said clearance portion and disposed in a plane perpendicular to the axis of said clearance portion at the opposite end thereof-from said bearing portion, said frame means also including a plate normally secured to said flange portion and having a central opening coaxial with said clearance portion, said plate having a lug extending axially therefrom and radially outwardly of said central opening into said clearance portion; a knob sleeve having a substantially annular cross section throughout its length, extending through and being rotatably mounted in said bearing portion and said openings,

and having an abutment portion extending outward from 10 2,795,948

the periphery of said sleeve within the space enclosed by said clearance portion and disposed to engage said lug on rotation of said knob sleeve to determine the normal sector of freedom thereof.

References Cited in the file of this patent UNITED STATES PATENTS Eiohel Apr. 18, 1933 Rayburn June 18, 1957 

